formSimilarQuery

Simple similarity query generators.
Takes every unique word and forms a boolean query where all words are optional.
After you get this you'll use to to query your IndexSearcher for similar docs.
The only caveat is the first hit returned should be your source document - you'll
need to then ignore that.

So, if you have a code fragment like this:
Query q = formSimilaryQuery( "I use Lucene to search fast. Fast searchers are good", new StandardAnalyzer(), "contents", null);

The query returned, in string form, will be '(i use lucene to search fast searchers are good').

The philosophy behind this method is "two documents are similar if they share lots of words".
Note that behind the scenes, Lucene's scoring algorithm will tend to give two documents a higher similarity score if the share more uncommon words.

This method is fail-safe in that if a long 'body' is passed in and
BooleanQuery.add() (used internally)
throws
BooleanQuery.TooManyClauses, the
query as it is will be returned.

Parameters:

body - the body of the document you want to find similar documents to

a - the analyzer to use to parse the body

field - the field you want to search on, probably something like "contents" or "body"